The overall aim of this project is to further understand the young child's psychological development in terms of his relationship with his mother and its cognitive-motivational and affective correlates. In addition to studying "attachment", this project will refine and develop assessment paradigms relating to free play, mastery motivation and affective organization. The major portion of the proposal involves cross-sectional studies with full-term and preterm infants. A longitudinal study will then be planned, partly based on these results, which will study the period from birth through three years, with attention to individual differences concerning processes related to emotional and cognitive-motivational health and deviance. A long-term goal is to relate an understanding of these processes to diagnosis and intervention in child psychiatry. The rationale for this study is two-fold. First, the applicant hopes to further understand relationships among infant attachment and cognitive- motivational and affective development by studies involving the use of a structured two-session paradigm. One session allows for the investigation of responses to strangers, free play behavior, and attachment behavior during separation and reunion with the mother. A second session consists of structured mastery motivation testing as well as Bayley developmental testing. Detailed scoring systems whose reliability and validity are known will be used to obtain measurements of attachment, cognitive-motivational development and affective development. Second, the applicant will study these features in preterm as well as full-term infants. Although there is evidence that the birth of a preterm infant has a major impact on the child's family, and in particular, on his relationship with his mother, systematic study is needed to understand social-affective developmental processes and to secure knowledge for designing intervention programs in the future. Finally, this project is considered to have significance for the newly appreciated field of infant psychiatry. Three varieties of attachment disorder in infancy have been proposed for inclusion in DSM-III. Their early recognition has important implications for secondary and tertiary prevention in mental health. Aside from the possible diagnostic usefulness of this research paradigm, an understanding of fundamental processes involved in normal attachment occurring in a variety of circumstances will enable us to develop rational treatment strategies.